CODEWITHSUNDEEP
sqlsql-server
mameesh
mameesh

Reputation: 3761

SQL Inner join 2 tables to 1 question

If I have the following line of code:

INNER JOIN #CompanyIdT t ON e.[companyId] = t.[Value] AND c.[CompanyId] = t.[Value]

Does this always join to the same companyId in the t table? So could e and c ever have a different CompanyId in 1 record?

Thanks

Upvotes: 0

Views: 110

Answers (2)

Cᴏʀʏ
Cᴏʀʏ

Reputation: 107606

You've described a transitive relationship:

If e.CompanyId = t.Value and c.CompanyId = t.Value, then e.CompanyId = c.CompanyId.

Since that statement is always true, you should never have a different CompanyId in any row in your query results. If you have duplicate Value values in t, you could get multiple rows with the same CompanyId.

Upvotes: 1

squillman
squillman

Reputation: 13641

No, e and c would never have a different value for companyID in a single record in the result set. They will always match t.Value, thus in your resultset it will always be the case that e.companyId = c.companyId = t.Value.

Upvotes: 2

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